1. Field of the Invention
The present invention relates to a video device, particularly to a video device for realtime pedaling frequency estimation.
2. Description of the Related Art
Nowadays, more and more people like to enjoy leisure activities. Among various outdoor leisure activities, biking is a sport very suitable to modern people, not only refreshing people in natural environments but also exercising their bodies. Many biking fans have established their teams for enjoying biking races or mountain biking.
While enjoying biking tours, bikers may have interest in some biking parameters, such as speed, distance, gear ratio, smoothness, balance, etc. The speed and distance of biking correlate with the physical performance and energy consumption of the biker. The conventional technology uses GPS (Global Positioning System) to track the path of biking, and uses the length of the path and the time of biking to calculate the speed. As long as the device can link to the Internet wirelessly, the conventional technology can estimate the speed of biking. However, the speed obtained by the conventional technology is unlikely to evaluate the physical performance and energy consumption of the biker because it does not take the factor of landforms into consideration. In fact, the pedaling frequency is more likely to indicate the physical performance and energy consumption of the biker.
The current bike cyclometers have been widely used to measure the biking speed and pedaling frequency. The improvement in the sampling technology has made the measurement of biking parameters more and more accurate. For an example, n pieces of magnets are annularly arranged in the gear disc or the crank of a bike, and the sensor detects the pass of n pieces of magnets each cycle of rotations of the gear disc, whereby the processing unit can work out the pedaling force and power output of the biker and the speed variation of the bike. For another example, a chain speed sensor and a chain tension sensor are respectively used to detect the speed and tension of the chain. As the chain is driven by the pedals, the frequency of chain rotation is identical to the frequency of pedal rotation. Therefore, the conventional technology can really detect the pedaling frequency.
In order to measure the pedaling frequency of the biker in an electric or magnetic induction way, sensors and magnets must be installed in a hike. Thus, the pedal mechanism, including the central shaft and the gear disc, must be greatly modified or replaced with dedicated components. Further, a complicated circuit must be installed to connect the hardware components with the sensors and the display device. Furthermore, the sensor installed in the fork rake must be very close to the magnets installed in the crank so as to undertake measurement accurately. Therefore, the installation is troublesome and complicated in the conventional technologies. Moreover, different brands of bikes need different pedal mechanisms and different wirings. Thus, the hardware cost is pretty high for detecting biking parameters in the conventional technologies. The abovementioned problems have impaired the application of the conventional bike cyclometers.
Accordingly, the present invention proposes a video device for realtime pedaling frequency estimation to overcome the abovementioned problems.